A method of manufacturing a 500ghz antenna element panel

Abstract

The application discloses a kind of 500GHz antenna unit panel manufacturing method, belong to antenna precision machining technical field.It uses numerical control optical machine tool to implement processing, using matlab software to simulate workpiece processing motion track, then the precision of simulation panel after processing is analyzed, after multiple optimization iteration, finally determine machine tool processing process parameter;A set of low stress panel tool fixture is designed, according to the actual situation of each panel in processing, ensure that the holding force received by the panel during processing is very small, almost no panel deformation;Machine tool spindle low speed dynamic balance adjustment, and panel assembly in situ dynamic balance adjustment, then can guarantee that panel is stressed evenly when machine tool high speed rotates;In order to improve the machining accuracy of machine tool and coordinate system, multiple tool setting parameter test is needed before machine tool processing, by adopting the above several measures, the final surface accuracy of unit panel is less than 0.005mm.Good features, meet the application scenarios of vertical polarization omnidirectional communication system.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of antenna precision processing, in particular to a super-high-precision antenna panel manufacturing method, which is suitable for micron-level mirror antenna panel processing. BACKGROUND

[0002] In 2001, Sweden, France, Finland and other countries launched the terahertz frequency band satellite Odin. It adopts a Gregorian form of double-reflector system as the antenna system of the satellite to receive electromagnetic signals, and the working frequency includes 118.25GHz-119.25GHz, 486.1GHz-503.9GHz and 541.0GHz-580.4GHz. In 2009, the European Space Agency (ESA) successfully launched the world's largest space observatory Herschel, which is used to explore the evolution of the universe. Herschel is the first space observatory to conduct photometry, mapping and spectroscopy in the submillimeter wave band. It carries three advanced terahertz detection devices including a spectrometer (PACS), a spectral photometric imager (SPIRE), and a far-infrared heterodyne receiver (HIFI), with an observation range covering 448GHz-5.3THz. The three devices share a 3.5m aperture Cassegrain form reflector system. The submillimeter wave frequency band giant single aperture telescope CCAT is one of the largest astronomical projects in the southern hemisphere in the United States in the coming years. CCAT has a design aperture of 25m and can perform multi-band observations, with a predicted working frequency range of 200GHz-1.5THz. It is mainly used to explore galaxy formation and cosmic evolution.

[0003] Domestic research in the field of millimeter wave, submillimeter wave and terahertz started relatively late, but through the development of multiple five-year plans, good results have been achieved in the fields of remote sensing, radio astronomy, etc. The Fengyun-3 (FY-3) and Fengyun-4 (FY-4) series of satellites are representative successful applications in the field of remote sensing in China. Among them, the FY-3 satellite series is the second generation of polar-orbiting meteorological satellite series in China, and the FY-3 has realized the first observation of water vapor (H2O) in the atmosphere in the terahertz frequency band in China. In August 2011, China's first submillimeter wave telescope CCOSMA for regular astronomical observation was built at an altitude of 4300m in the Tibet Yanzhuolin astronomical observation station. CCOSMA can detect high-frequency molecular spectral lines and is mainly used for observing stars submerged in interstellar dust. The main reflector of CCOSMA has a diameter of 3m and is composed of 18 aluminum panels, and the surface precision after assembly is better than 20μm. CCOSMA is equipped with 5 ports and can carry 230GHz, 345GHz, 490GHz, 660GHz and 810GHz modules. At present, it can collect 230GHz and 345GHz signals.

[0004] As the operating frequency increases, the surface accuracy requirements for the antenna's main unit panel also increase. Therefore, researching a manufacturing method for a 500GHz antenna panel is particularly important. Although my country's processing and manufacturing capabilities have made great progress, further research is still needed for ultra-precision machining, especially ultra-precision machining under the interaction of multiple factors such as temperature, humidity, gravity deformation, and vibration, in order to meet the electrical performance requirements of high-frequency antennas. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide a method for manufacturing an ultra-high precision aluminum antenna panel. The panel has the advantages of high surface accuracy, light weight and high smoothness. The processing method adopted has good processability, controllable parameters and is easy to implement.

[0006] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows:

[0007] A method for manufacturing a 500GHz antenna element panel specifically includes the following processes:

[0008] Step 1: Select panel raw materials, machining tools, low-stress tooling fixtures, and CNC optical machine tools;

[0009] Step 2: Verify the process parameters of the CNC optical machine tool, select a scaled-down sample for processing; then, the contour analyzer manufacturer will analyze and calculate to ensure that the surface accuracy reaches 3µm.

[0010] Step 3: Place the panel material on the worktable of the CNC optical machine tool, align it according to the outer edge of the panel material, and place the panel material at the rotation center of the machine tool spindle.

[0011] Step 4: According to the drawings, use a CNC optical machine tool to rough machine the panel to achieve the desired dimensions, leaving a machining allowance of 3mm on each side;

[0012] Step 5: Remove the roughly machined panel from the CNC optical machine tool and place it in a heat treatment furnace for aging treatment;

[0013] Step 6: Place the panel horizontally back on the worktable of the CNC optical machine tool, and install low-stress tooling fixtures at each corner;

[0014] Step 7: Perform precision machining on the panel outline, back cavity, bottom surface, and side reference planes using a CNC optical machine tool;

[0015] Step 8: The finished panel undergoes another aging treatment;

[0016] Step 9: Grind the bottom surface of the panel to achieve a flatness of 0.005mm, a flatness of 0.005mm for the side reference plane, and a perpendicularity of 0.005mm.

[0017] Step 10, the panel is installed on the numerical control optical machine tool workbench again, and the low stress tooling fixture is installed, in order to ensure the machining precision of the panel, the numerical control optical machine tool is precisely tool set, so that the tool movement track is accurately aligned with the normal of the front surface of the panel, and the angular tool setting precision needs to be less than or equal to 0.1 degrees;

[0018] Step 11, the panel parabolic surface is precisely machined again, the room temperature is controlled at 20 degrees, and the panel surface type precision is finally less than 0.005 mm through multiple iteration machining.

[0019] Further, the low stress tooling fixture in the steps 6 and 10 comprises a wrap angle tooling; the wrap angle tooling is two baffles with an included angle; the outer side of one baffle is provided with a rigid clamp; and the outer side of the other baffle is provided with a flexible clamp.

[0020] Further, the low stress tooling fixture in the step 6 is installed, and the specific process is as follows:

[0021] Step 601, the wrap angle tooling is installed;

[0022] Step 602, the rigid clamp is installed; and the rigid clamp is connected with the panel side surface reference surface to become an integral whole;

[0023] Step 603, then the flexible clamp is in three-point contact with the rigid clamp.

[0024] Further, the aging treatment process of the steps 5 and 8 is as follows: 130 degrees-150 degrees, keeping for 5 hours, and then slowly cooling in the furnace.

[0025] The beneficial effects of the present application are as follows:

[0026] (1) Panel using CNC optical machine tool processing, using high response frequency, high resolution tool control technology, implementation of off-axis parabolic turning based on precise motion control method. Using matlab software to simulate the workpiece processing trajectory, then analyze the precision of the simulation panel after processing, after several optimization iterations, finally determine the machine tool processing parameters. In the machine tool processing, the workpiece in the design coordinate system of two-dimensional surface equation is converted to cylindrical coordinate system of three-dimensional surface equation, and the coordinate transformation is carried out to move the workpiece to the machining center. The room temperature in the machine tool processing room is kept at 20 degrees. First, rough milling of the panel shape and back cavity size, single side allowance 3mm; second, aging treatment, the temperature in the quenching furnace is kept at 130-150 degrees for 4 hours, then furnace cooling; third, milling of the panel shape and back cavity size, single side allowance 1mm, the same aging treatment under the same conditions; then find the panel on the machine tool workbench, precision milling of the panel front surface type precision ≤0.02mm, milling of the bottom surface and side surface reference plane, flatness to 0.01mm; panel fine grinding of the bottom surface and side surface reference plane to 0.005mm; precision milling of the panel front surface type, through several iterations of fine processing, panel surface type precision ≤0.005mm; finally, the panel is precisely measured on the three coordinate measuring machine, to detect whether the surface type precision is within 0.005mm.

[0027] (2) Design low stress tooling fixture, in order to ensure that the panel fixture stress change is small before and after installation, design high precision panel corner clamping tool, rigid clamping with panel contact surface flatness <0.005mm, perpendicularity <0.005mm, at the same time, the panel side surface reference flatness <0.005mm, perpendicularity <0.005mm, the two contact surfaces are tightly fitted, then gently twist three bolts on one side of each corner, at the same time, use the dial indicator to monitor the deformation of the panel side surface, use the torque wrench to tighten the bolts, and adopt the symmetrical cycle tightening method, install the fixed tooling on both sides of each corner, the contact between the fixed tooling and the corner tooling adopts two ways: one side is plane contact, the other side is spherical point contact, in this way, through plane contact, one side of the panel can be fixed, at the same time, the other direction of the panel side is installed with flexible clamping, so that the panel is not stressed or stressed very small. In general, through the design of such low stress tooling fixture, the force acting on the panel is very small.

[0028] (3) The panel processing reference is finely ground by diamond. In order to make the panel surface accuracy better than 0.005mm, high-precision processing reference and installation reference are needed. Therefore, the method of fine grinding by diamond + three-coordinate measurement is adopted. The panel is ground gradually by the method of coarse grinding first and then fine grinding. Then the panel is precisely scraped by a scraper. The three-coordinate measuring machine is used to measure at each stage. Through repeated fine grinding and measurement, the flatness of the panel processing reference and installation reference is controlled within 0.005mm.

[0029] (4) A variety of machine tool dynamic balance adjustment methods are adopted. In order to ensure the balance of the panel during processing in the machine tool, the low-speed dynamic balance of the main shaft is measured and adjusted. The in-situ dynamic balance adjustment is performed again after the panel tool positioning. The in-situ dynamic balance adjustment of the panel assembly is performed after the panel is installed. The in-situ dynamic balance of the machine tool in the final state of panel processing is gradually achieved.

[0030] (5) In order to achieve 0.005mm surface accuracy and mirror surface effect, wear-resistant and small-radius arc machining tools are needed. Therefore, a Canadian KY radius 50nm diamond tool is customized. The tool is used for machining to realize close contact between the tool arc and the panel, prevent the generation of wavy machining tool marks, and the panel has high smoothness.

[0031] (6) In order to improve the machining accuracy and coordinate system of the machine tool, the tool is measured before machining. The front and rear left and right tool RMS value is 0.3um. The workpiece is aligned with the outer circle by 3um. The machine tool is machined at an angle of 0.1 degrees. In this way, the consistency of the panel front curve and the design curve is ensured.

[0032] The above process technology is controllable in process parameters and stable in technical performance, and is suitable for batch production. BRIEF DESCRIPTION OF DRAWINGS

[0033] Figure 1 is the front view of the antenna unit panel of the application;

[0034] Figure 2 is the bottom view of the antenna unit panel of the application;

[0035] Figure 3 is the side reference plane view of the antenna unit panel of the application;

[0036] Figure 4 is the angular shape view of the antenna unit panel of the application;

[0037] Figure 5 is the panel and low-stress tool fixture view of the application.

[0038] In the figure: 1, fixed block, 2, rigid clamping, 3, flexible clamping, 4, corner tool, 5, panel. DETAILED DESCRIPTION

[0039] The technical solutions in the embodiments of the present application are clearly and completely described below with reference to the drawings and examples, but the embodiments described herein are only some of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present application.

[0040] The present application discloses a 500GHz antenna unit panel manufacturing method, which adopts numerical control optical machine tool to implement processing, utilizes tool control technology with high response frequency and high resolution, and implements off-axis parabolic turning processing method based on accurate motion control. Matlab software is used to simulate the workpiece processing motion track, and then the precision after the simulation panel processing is analyzed. After multiple optimization iterations, the machine tool processing process parameters are finally determined. A low-stress panel tool fixture is designed. According to the actual situation of each panel in the processing, the holding force of the panel in the processing process is ensured to be small, and almost no panel deformation is generated. The unit panel fine grinding process ensures that the panel bottom flatness is less than 0.005mm, the side reference flatness is less than 0.005mm, and the perpendicularity is less than 0.005mm. The low-speed dynamic balance adjustment of the machine tool spindle and the in-situ dynamic balance adjustment of the panel assembly can ensure that the panel is uniformly stressed when the machine tool rotates at high speed. In order to realize the surface type precision of 0.005mm and the mirror surface effect, a radius of 50nm arc diamond tool is customized to prevent the generation of wavy processing tool marks, and the smoothness of the panel is also high. In order to improve the processing accuracy of the machine tool and the coordinate system, multiple tool setting parameter tests are required before the machine tool processing. Through the above measures, the final surface type precision of the unit panel is less than 0.005mm.

[0041] The present application utilizes tool control technology with high response frequency and high resolution, and implements off-axis parabolic turning processing method based on accurate motion control.

[0042] The present application designs a low-stress tool fixture combined with rigid clamping and flexible clamping.

[0043] The present application discloses a dynamic balance method for in-situ dynamic balance adjustment of the panel tool.

[0044] The present application customizes a diamond tool with an arc radius of 50nm.

[0045] The present application discloses a parabolic panel surface type precision better than 0.005mm, which is suitable for antenna working frequency reaching 500GHz.

[0046] REFERENCE Figures 1 to 5A 500GHz antenna unit panel manufacturing method, which uses a numerical control optical machine tool to implement processing, uses tool control technology with high response frequency and high resolution to implement off-axis parabolic turning processing method based on precise motion control. The workpiece processing motion trajectory is simulated using matlab software, and then the precision after the simulation panel processing is analyzed, and after multiple optimization iterations, the machine tool processing process parameters are finally determined. A three-point contact low-stress tool fixture is used, and a flexible connection method is used. The panel is finely ground to ensure that the panel bottom surface flatness, side reference flatness, and perpendicularity are all within 0.005mm. Adjust the machine tool spindle low-speed dynamic balance and the panel assembly in-situ dynamic balance. The machine tool processing angular tool setting is better than 0.1 degree, and the above various technical measures are taken, and finally the unit panel surface accuracy is better than 0.005mm.

[0047] A 500GHz antenna unit panel manufacturing process:

[0048] 1) A low-stress tool fixture is designed, which combines elastic clamping and rigid clamping to minimize the mounting and holding force of the panel;

[0049] 2) In order to realize the close contact of the tool arc and the panel, and prevent the generation of wavy processing knife marks, the machine tool processing tool selects a Canadian KY circular arc diamond tool with a radius of 50nm;

[0050] 3) Since the antenna is very sensitive to the weight and thermal expansion and contraction of the panel, an aluminum plate material with a relatively low thermal expansion coefficient, 6061-T651, is selected;

[0051] 4) The panel is manufactured using a numerical control optical machine tool, in order to reduce the influence of centrifugal force generated when the machine tool workbench rotates, the machine tool spindle is adjusted using low-speed dynamic balance;

[0052] 5) In order to verify the machine tool processing parameters, a scaled-down sample of 200mm x 200mm is selected, and according to the previously determined process method, the contour instrument factory calculates the surface accuracy to be 3um, therefore, the process parameters meet the panel processing accuracy requirements;

[0053] 6) Place the panel raw material on the machine tool workbench, align the outer edge of the raw material, and place the panel at the center of rotation of the machine tool spindle;

[0054] 7) According to the design drawing, the machine tool rough turning processes the panel dimensions, leaving a processing allowance of 3mm on one side;

[0055] 8) Then remove the panel from the machine tool and place it in a heat treatment furnace for aging treatment: 130-150 degrees for 5 hours, then slowly cool with the furnace;

[0056] 9) Put the panel back on the machine tool workbench, install the low-stress tooling fixture, first connect the rigid clamping with the panel side reference surface to become one, then make the flexible clamping contact with the rigid clamping three points, so that one corner of the panel is stressed in the X direction and almost not stressed in the Y direction, and similarly, install the low-stress tooling fixture in the other three corner directions symmetrically, finally the panel is balanced in the whole and in the low-stress clamping state, and the influence of the holding force is minimized as much as possible;

[0057] 10) After taking the above measures, start precise machining of the panel shape, back cavity, bottom surface and side reference plane, then perform aging treatment again, and the treatment method is the same as above;

[0058] 11) In order to obtain higher panel surface precision, the panel bottom surface needs to be finely ground as the reference plane for panel machining and installation, the bottom surface flatness is 0.005mm, the side reference plane flatness is 0.005mm, and the perpendicularity is 0.005mm;

[0059] 12) Install the panel on the machine tool workbench again and install the corresponding low-stress tooling fixture, in order to ensure the machining precision of the panel, the machine tool needs to be precisely tool-set, so that the tool movement trajectory is accurately aligned with the normal of the panel front surface, through calculation, the angular tool-setting accuracy needs to be ≤0.1 degree;

[0060] 13) In order to achieve 0.005mm surface precision, the panel parabolic surface is precisely machined again, the room temperature is controlled at 20 degrees, and through multiple iterative machining, the panel surface precision is finally less than 0.005mm;

[0061] 14) After the panel is machined, it needs to be transported to a three-coordinate measuring machine for third-party detection of the panel surface precision, in order to verify whether the final panel surface precision meets the index requirements.

Claims

1. A method of manufacturing a 500 GHz antenna element panel, characterized by, Specifically comprising the following processes: Step 1, selecting panel raw materials, processing tools, low-stress tooling fixtures and numerical control optical machine tools; Step 2, verifying the process parameters of the numerical control optical machine tool, selecting a scaled sample for processing; and then analyzing and calculating the profile instrument factory to make the surface accuracy reach 3um; Step 3, placing the panel raw material on the workbench of the numerical control optical machine tool, aligning the outer edge of the panel raw material, and placing the panel raw material at the center of rotation of the main shaft of the machine tool; Step 4, according to the drawing, the numerical control optical machine tool roughens the panel size, and leaves a processing allowance of 3mm on one side; Step 5, dismounting the roughened panel from the numerical control optical machine tool and placing it in the heat treatment furnace for aging treatment; Step 6, placing the panel horizontally on the workbench of the numerical control optical machine tool, and installing low-stress tooling fixtures at each corner; Step 7, precisely processing the panel shape, back cavity, bottom surface and side reference plane through the numerical control optical machine tool; Step 8, aging the precisely processed panel again; Step 9, grinding the panel bottom surface to make the bottom surface flatness reach 0.005mm, the side reference plane flatness reach 0.005mm, and the perpendicularity reach 0.005mm; Step 10, installing the panel on the workbench of the numerical control optical machine tool again and installing low-stress tooling fixtures, in order to ensure the processing accuracy of the panel, accurately setting the tool of the numerical control optical machine tool, making the tool motion trajectory and the front normal of the panel accurately aligned, and the angular tool setting accuracy needs to be less than or equal to 0.1 degrees; Step 11, precisely processing the panel parabolic surface again, controlling the room temperature at 20 degrees, and through multiple iterative processing, the panel surface accuracy is finally less than 0.005mm.

2. The method of claim 1, wherein, The low-stress tooling fixture in steps 6 and 10 comprises an angle covering tool; the angle covering tool is two baffles with an included angle; the outer side of one baffle is provided with a rigid clamp; and the outer side of the other baffle is provided with a flexible clamp.

3. The method of claim 2, wherein, The specific process of installing the low-stress tooling fixture in step 6 is as follows: Step 601, installing the angle covering tool; Step 602, installing the rigid clamp; making the rigid clamp and the panel side reference plane connected as a whole; Step 603, then three-point contact of the flexible clamp and the rigid clamp.

4. The method of claim 1, wherein, The aging treatment process of steps 5 and 8 is as follows: 130-150 degrees, maintaining for 5 hours, and then slowly cooling with the furnace.

5. The method of claim 1, wherein, In step 1, in order to realize the close contact of the tool arc line and the panel, and prevent the generation of wavy processing tool marks, the machine tool processing tool selects a Canadian KY circular diamond tool with a radius of 50nm; Since the antenna is very sensitive to the weight and thermal expansion and contraction of the panel, an aluminum plate material with a relatively low thermal expansion coefficient, 6061-T651, is selected; The main shaft of the numerical control optical machine tool is adjusted by low-speed dynamic balance.

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